Gyroscopic navigational instrument



Sept.I 6, 1938.l D. G. K. Moss 2,28,956

GYROSCOPIC NAVIGATIONAL INSTRUMENT Filed Jan. 16, 1937 4 Sheets-Sheet l Douglas George. Kmq Moss.

INVENTOQ sept. s', 1938. D Q K MQSS. 2,128,956

NAVIGATIONAL Filed Jan'. 41e, 1957 4 sheets-sheet 2 Sept. 6, 1938. D. G. K, Moss 2,128,956

' GYROSCOPIC NAVIGATIONAL INSTRUMENT A Filed Jan. 16, 1957 4 Sheets-Sheet 3 DOUMS GUNS@ MOSS INVENTOI,

sept. 6, 1938. D, 'G K Moss 2,128,956

GYROSCOPI C NAVI GAT I ONAL INSTRUMENT Filed Jan. 16, 19,57 4 sheetssheet 4 i Daulobeorgemn' Moss I N VE NTOK Patented Sept. 6, 1938 UNITED STATES` Graoscorlc NAvrGa'rIoNAL INSTRUMENT.

Douglas George King Moss, Sanderstead, England Application January 16, 1937, Serial No. 120,907 In Great Britain April 8, 1936 9 Claims.

This invention relates to improvements in gyroscopic navigational instruments of the artificial horizon or gyro vertical type more particularly intended for use on aircraft, and watercraft (both surface and under-water craft).

The. principal object of the invention is to provide novel indicating means for such instrument whereby the pilot may observe the trim of his craft pictorially. A further object of this invention is to provide novel indicating means for suchinstruments which will give an exaggerated movement of the data elements in order that even slight deviations from horizontal flight will be clearly indicated to the pilot. f

l5 According to this invention, the instrument is provided with a pivoted ghost ring, adapted to lie over and away from a front dial, which ring bears a pictorial representation `of an aeroplane l and is interconnected with an inner glmbal.

`According to'another form of this invention', a

pictorial representation of the craft and a representation of the horizon are movable by the gimbals in opposite directions away from one another when the craft on which the instrument is 26 mounted departs `from the horizontal. A

According to a further feature of the invention, a third indicator is provided and adapted'to'operate in conjunction with the indication given by thepictured aeroplane.

In order that this invention may be the more clearly understoodand readily carried into effect, I will proceed to describe two embodiments of the same as applied to an air driven and controlled gyroscopic navigational instrument, with reference to the accompanying drawings, which are ^given by way of example only and -not of limitation.

In these drawings: Figure 1 is a vertical section throughl a gyro 4o vertical and indicator or ghos ring,

Figure 2 isy a part sectional plan of the same with the casing removed.

' Figure 3v is a iront view of the indicator, without the casing, in normal position,

kiii Figure 4 issimilar to Figure 3 but aslseen when' the craft is. banking and climbing,

Figure5 is to Figure 3; but as seen when the craft `has banked 90, liigure' 6 is a iront view of Figure 1, on a re- 450' duced scale, including the casing,-

- Figure 7 is a part sectional plan, similar to -Figure 2, showing another' form of indicator,

Figure 8 is asecticn oi' the -line-lI--II of Figure 7 looking in the direction of the arrows. J

Figure 9 is a front view of the instrument shown in Figures 7 and 8, with the indicating means in normal position, and

Figure 10 is similar to Figure 9, but showing the indicating means displaced as in climbing.

In the description which follows all like parts 5 are referred to by like reference letters.

Referring to the drawings generally, an airdriven gyro Wheel a is rotatably mounted on a vertical spindle al in an air-tight casing bfwhich constitutes an -inner gimbal and which is rotatl0 ably mounted on inner gimbal trunnions c carried by an outer semi-circular or U-shaped gimbal d which in turn is rotatably'mounted by means of a hollow spindle d1 in spaced bearings e forming an outer gimbal trunnion. This trunl5 nion is housed in the back of the casing f. The axes of the `trunnions intersect the\vertical axis ofthe gyro wheel at the centre ofthe moving system.

By the use of only one trunnion bearing for 20 the outer gimbal, the instrument case may revolve unhindered about-the mechanism, whereby a complete roll or a'series of rolls, ii-the instrument be mounted on an aircraft, may be executed without upsetting the instrument and the -instru- 25 ment will function when the aeroplane is steeply banked, for example, to 90 from normal and when it is inverted.

The gyroscope is controlled by rolling valves g, mounted on central pins g1 which can roll in- 30 straight-line slots yz in the valve chamber g3, motive air being drawn into the instrument and fed to the gyro-wheel and to the valve chambers g3. 'I'.wo valve chambers are provided and the rolling axes of the valves are arranged at right 35 angles to oneanother. Each` valve. chamber is provided at each end with vair--exit-orifices g4 arranged so that normally they'are open tc an equal extent. In order to reduce friction between the ends of the valve and the valve chamber, the ends 40 of the pins al are radiused and burnished and they are arranged to contact lightly with plugs g5 which are inserted in the .cheeks of the valve chamber so as to keep the ends of the valve clear of the cheeks. These plugs also serve to prevent escape of air through the slots a2.

The air. which drives the gyro-wheel, is subsequently controlled by the valves so .as to producean erecting torque should the wheel spinning axis be displaced from vertical. Usually, a Venturi suction tube or other table means is attached to the tube f1, and in ight air is drawn in through the hollow spindle d1. at the inner end of which the air-stream divides andpasses through a channel d3 in each horn of the gimbal d and then through 55 inlet orices in the inner gimbal bearings whence it passes through the trunnion and issues through an exit orice as a vjet which impinges on and drives the gyro wheel. As this construction of the horn of the gimbal d and the trunnion is the same on each side of the gyro wheel it will suiiice to identify the parts shown in section in Figures 2 and '7; in those gures d2 is the air-channel, c1. are the inlet orifices and c2 is the exit orifice. The air-stream passes from the casing b into the valve chambers g3. When the gyro wheel axis deviates from the? true vertical one or both of the valves will roll (depending upon whether the deviation is in a direction fore-and-aft or athwartships, or in both directions) thus uncovering a greater areal of the exit orifices g4 at one end of the valve chamber and covering a greater area of the exit orices g4 at the other end of the valve chamber, and thereby varying the intensity of the issuing air-jets and consequently producing the desired erecting torque. In the case of excessive deviation the exit orifices g4 will be completely opened at one end and completely closed at the other end. The elements of the construction set forth in the foregoing have been shown and claimed in applicants prior U. S. Patent 2,036,229. y

Referring now to the 4present invention and particularly to Figures 1 to 6, on a bifurcated bracket q secured to the casing f with the limbs q1, q2 thereof embracing the instrument, there is pivotally mounted at r2, on an axis parallel to or coincident with the inner gimbal axis when in normal position, a support r which is hereinafter called a ghost ring. An arcuate dial ol with a vertical slot o ther in is mounted on a spider o2` fixed to the outer gimbal d. The ghost ring r is of U-channel section and is bent into substantially arcuate form to lie over and away from the arcuate dial o1 of the instrument, it being pivoted to the'` bracket by solid elements lying in the channelling 4at `the ends thereof. suitably shaped weights r1 are arranged on the solid elements on l the opposite sides of the pivotal point to accurately balance the ghost ring r. On its outer Surface the ghost ring bears a pictorial representations of a rear view of an aeroplane conveniently out out from a piece of metal and suitably coloured and marked. 4

A rod n is attached to the inner gimbal b so as to extend at right angles to the gyro axis and also at right angles to the trunnion bearings c. This rod n extends through the slot o in the dial o1 and at its end takes into the channelling of the ghost ring r which thus normally lies in the plane of the trunnion d1. -When there is any deviation from the true level in the fore-and-aft direction, relative movement takes place between the dial o1 and the rod n, the latter moves in the slot o. During any sideways displacement of the rod n due to banking of the aeroplane, the end of vthe rod n slides along in the channelling' in the ghost ring r.

Thus the device gives a qualitative reading as the wings of the pictured aeroplane will always be parallel toI those of the craft on which the instru- .ment is fitted. Normally the ghost ring r will lie `over the horizon line s1 whichis painted on the dial o1 and roll yand pitch may be noted by noting the position of the pictured aeroplane with respect to the horizon line s1.

When, however, the aeroplane is steeply banked, the pictured aeroplane s will lie over on its side and when the aeroplane is 90 out of normal will not indicate to the pilot the direction of flight upwardly orv downwardly. To overcome this disadvantage there is provided on the rod n,

at a point intermediate the dial o1 and the ghost ring r, a diamond shaped piece n1 conveniently coloured white and arranged with itsl major axis parallel to the ring r. During all normaloperations the diamond n1 is hidden behind the pictured aeroplane s (as indicated by dotted lines in Figure 3), but when the craft is steeply banked the acute angle tips of the diamond n1 will appear on either side of the ghost ring r and will move away from the body of the pictured aeroplane to one side or the other according to the degree and direction of iiight in an upward or downward direction. Thus, in Figure 4, which shows the parts in the position they would assume when the aeroplane is making a left-hand climbing banked turn, the tips of the diamond nl are seen on each spite 'of the fact that the pictured aeroplane moves l only in the one dimension.

IReferring now to Figures '7 to 10, instead of the horizon line s1 painted on the dial o1, a representation of the horizon is given by the members h, hereinafter referred to as the horizon" ring, which extend through slots o3 in the dial o1. In the form shown the horizon ring h is pivoted at h1 to the outer gimbal d and is balanced by the counterpoise weights h2. A. pin i on the inner gimbal acts in the slot 7' in the bifurcated ends of the horizon ring. The horizon ring h normally lies in the horizontal plane and-behind the ghost ring. r, above and below which the edges of the horizon ring h may be seen (Figure 9). If the craft on which the instrument is mounted commences to climb, the axis of the spindle d1 of the outer gimbal d, as seen in Figure 8, is tilted causing a rotation of the outer gimbal about the inner gimbal and the axis c in a clockwise direction and the rod n Vwill hold the ghost ring r substantially stationary while the dial o1 moves in a downward direction-to give an apparent upward movement of the aeroplane. The movement of the outer gimbal would cause the pivots h1 to move downwards, thus causing the pins i to rock the members h about the pivots h1,so that the horizon ring would move downwardly with respect to the dial o1 and away from the pictured aeroplane s, as may be seen from Figure 10. 'I'he pivots h1 and the pins z' could be transposed, that is, the pins 2' could be on .the outer gimbal and the pivots h1 on the inner gimbal, and the' same result be obtained. i

The diamond'n1 acts exactly as describedvwith reference to Figures 3 to 5. y

The indicating means may be employed with other similarly acting erecting means or other instruments having the same characteristics, for example, an electrically driven instrument.

I claim:

1. In a gyroscopic navigational instrument, a

semi-circular outer vgimbal supported at the rear4 at thefront of the instrument, said dial having a-,iaaose Atrunnion for movement about a fore and aft ams,

an inner' gimbal pivoted to said outer gimbal on a. transverse axis; a gyro Wheel having a normal vertical spin axis carried by said inner gimbal, a dial carried by said outer gimbal at the front of the instrument, said dial having a vertical slot, a

member of U-section pivoted on an axis normally f coincident with said transverse axis and extend-' ing across in front of said dial so as to provide a transverseguide channel open towards the latter, a pictorial representation of an aeroplane carried by said member over said dial, and a. rod attached to said inner gimbal extending through said slot and normally lying coincident with the axis of said single trunnion, the free end of which rod lies in the channel in said pivoted member so as to stabilize the latter against pitching movements.

3. In a gyroscopic navigational instrument, an outer gimbal supported at the rear by a single/ trunnion for movement about a fore and aft axis, an inner gimbal pivoted to said outer gimbal on a transverse axis, a gyra-Wheel having a normal vertical spin axis carried by said inner gimbal, a dial carried by said outer gimbal at the front of the instrument, said dial having a vertical slot, a member pivoted on an axis normally coincident with said transverseaxis and extending across in front of said dial, a pictorial representation of an aeroplane imounted on said member over said dial, means extending through said slot for slidably connecting said member with said inner gimbal whereby the latter is stabilized against pitching movements, pivoted elements representing the horizon also extending across in front of said dial and normally behind said pivoted member, and means controlled by said gyro wheel for moving said elements in the same direction asA said dial but to an exaggerated extent when relativemovements take place between the gimbals.

4. In a gyroscoplc navigational instrument, an outer gimbal supported 4at the rear by a single trunnion for movement about a' fore and aft axis, an inner gimbal pivoted-to said outer gimbal on a transverse axis, agyro wheel havingI a normal vertical spin axis carried by said inner gimbal, a' dial carried by said outer gimbal at the front of the instrument, saiddial having a vertical slot, a member of U-section pivoted on an axis normally coincident with saidtransverse axis and extending across in front of said dial so as to provide a transverse guide channel open towards the latter, a pictorial representation of an aeroplane carried by said member over said dial, a rod attached to said inner gimbal extending through said slot and normallyl lying coincident with the axis of said single trunnion, the free end of which rod lies in the channel in said pivoted member to stabilize the latter against pitching movements. a representation of the horizon comprising pivoted elements extending through slots in andlying across in front of said dial, and means controlled by said gyro wheel for moving said elements' in opposite directions on relative movement oi said inner and outer gimbals.

u coincident with said transverse axis and mally behind said pivoted member 5. In a gyroscopic navigational instrument, an outer gimbal supported at the rear by a single trunnion for movement about a fore and aft axis, an inner gimbal pivoted to said outer gimbal on a transverse axis, a gyro wheel having a normal vertical spin axis carried by said inner gimbal, a dial carried by said outer gimbal at the iront of the instrument, said dial having a vertical slot, a

member of U-section pivoted on an axis normally extending across in front of said dial so as to provide a.7

transverse guide channel open towards, the latter, a pictorial representation of an aeroplane carried by said member over said dial, a rod attached to said inner gimbal extending through said slot and normally lying coincident with the axis of said single trunnion, the free end of which rod lies in the channel in said pivoted member to stabilize the latter against pitching movements, a diamond shaped element mounted on said rod between said dial and said pivoted memv ber` and normally hidden behind the pictured aeroplane, a representation of the horizon norcomprising pivoted elements extending through slots in and lying across in, front oi said dial, and means controlled by said gyro wheel for moving said elements on relative movement oi said inner and outer gimbals.

6. In a gyroscopie navigational instrumenta semi-circular outer gimbal supported at the rear by -a single trunnion for movement about a. fore and aft axis, an inner gimbal pivoted ,to said outer gimbal on a transverse axis, a gyro wheel having a normal vertical spin axis carried by said inner gimbal, a dial carried by said outer gimbal at the front of the instrument, said dial having a vertical slot, a member pivoted on anaxis normally coincident with said transverse axis and extending across in front of said dial, a pictorial representation of an aeroplane mounted on said member over said dial, means extending through said slot for sildably connecting' said member with said inner gimbal whereby the latter is stabilized against pitching movements, and an indicator carried by said connecting means and visible behind the representation of the aeroplane when the craft carrying the instrument is steeply banked. y

7. In a gyroscopic navigational instrument, an outer gimbal supported at the rear by a single trunnion for movement about a fore and aft axis, an inner gimbal pivoted tq said outer gimbal on a normally lying coincident with the axis of said single trunnion, the free lend of which rod lies in the channel in said pivoted member so as to stabilize the latter against pitching movements, and an indicator` mounted on said rod intermediate said dial and said member and visible behind the representation of the aeroplane when the craft carrying the instrument is steeply banked.

8.In a gyroscopic navigational instrument, an outer gimbal supportedvat the rear by a single trunnion for movement about a fore and aft axis,

an inner gimbal pivoted to said outer gimbal on` outer gimbals, and an indicator front of said dial, a pictorialrepresentation of an` aeroplane mounted on said member over said dial, means extending through said slot for slidably connectingy said memberwith said inner gimbal whereby the latter is stabilized against pitching movements, pivoted elements representing the horizon also extending across in front of said dial and normally behind said pivoted member, means.

controlled by said gyro wheel for moving said elements on relative movement oil said inner and rod intermediate said dial and said member and visible behind the representation of the aeroplane when the craft carrying the instrument is steeply banked.

9. In a'gyroscopic navigational instrument, an

mounted on said' outer gimbal pivoted about a fore and aft axis, an inner gimbal pivoted to said outer gimbal about a transverse axis, a gyro wheel having a normally vertical spin axis carried by said inner gimbal, a

member pivoted about an axis normally coincident with said transverse axis, a pictorial representation of an aeroplane mounted on said meme ber, means connectingsaid member with the inner gimbal so as to stabilize said member against pitchingmovements, an element arranged near theirepresentation of the aeroplane to represent the horizon-and pivoted on one of said glmbals about an axis parallel to said transverse axis, and connected to the other gimbal so as to' be displaced by relative movements between the gimbals in the direction of'the outer gimbal tota greater extent than the latter, said pictorial representation of the aeroplane and s aid representation of-the horlzonvboth being movable in opposite directions relative to one another.

DOUGLAS QEoRGE KING Moss. 

